Ferdinand gerhard wiechmann



UNITED STATES PATENT OFFICE.

FERDINAND GERHARD WIECHMANN, OF NEIV YORK, N. Y.

TREATENG SUGAR OR OTHER SOLUTIONS.

SPECIFICATION forming part of Letters Patent No. 553,974, dated February4, 1896.

Application filed May 20, 1895. Serial No. 549,991. (No specimens.)

To all whom it may concern:

Be it known that l, FERDINAND GERHARD \VIECHMANN, a citizen of theUnited States, residing at the city, county, and State of New York, haveinvented a Process of Treating Sugar and other Solutions, of which thefollowing is a specification.

My invention relates to a process of treating sugar and other solutionswhereby the impurities contained therein are removed.

Generally my improved process consists in subjecting the solutions fromwhich the impurities are to be removed to the action of a filteringagent and simultaneously or successively to the action of chemicals,which latter entering into combination in the solution form an insolubleprecipitate, which precipitate acts in the nature of a filtering agentand mechanically tends to separate the impurities.

I will now describe my improved process as employed by me in thetreatment of sugar solutions.

The sugar solution to be purified may be of any desired degree ofdensity up to 1.415. To such a solution there is added the filteringagentz'. 6., diato naceous earth from 0.01 per cent. to 2.5 per cent. ofare weight of the dry substance contained in the solution. The amount ofdiatomaceous earth used will depend upon the namTrWfiTcharacter'of thesolution to be purified-2'. 8., the amount of impurities contained,which can easily be de termined by any one skilled in the art to whichthis invention belongs and by the employment of means commonly known.The diatomaceousearth employed is preferably such as has been washed orburnedin other words, such as has had its mechanical impurities removed.I do not limit myself, however, to the use of treated diatomaceousearth, as the earth in the condition in which it comes from the minesmay be employed. The diatomaceous earth acts as a filtering agent in twoways: first, when mixed with the solution and in settling, by attractingand carrying down with it the mechanically-suspended impurities in thesolution, and, secondly, by forming a layer or deposit on thefilter-bags or "lil'ter-clothsfflvliereby there is secured more perfectmechanical filtration than can be obtained by any other known filteringagent.

salt used is one whose acid radical is P0 which is soluble in water, andwhich, when brought in contact with another chemical as, for instance,calcic hydrate-forms an insoluble precipitate. Of such salts may bementioned orthophosphoric acLd,and. monocalcic phosplmtee l hequa'fitity of the salt 'w-hi-ch-Iunay' use'w'ill vary from 0. 01 percent. to 2.0 per cent. of the weight of the dry substance containedoriginally in the solution under treatment. The amount of the salt soused will also depend upon the nature and character of the solutionthatis to say, the greater the amount of contained impurities and the moreviscous their nature the greater the amount of the diatomaceous earth aswell as of the chemicals which may be required. This can only bedetermined by actual experiment with limited quantities of the materialto be defecated. After adding the phosphoric salt I add to the solutionan alkaline earth, such as lime (calcic hydrate) in any form desired,preferably in that known as the milk of lime, and in quantity sufficientto combine chemically with and precipitate the salt or salts ofphosphoric acid employed.

The quantity of lime used is in accordance with the chemical conditionsexhibited in the following formula:

that is to say, for every one hundred and ninety-six parts by weight oforthophosphoric acid two hundred and twenty-two parts by weight ofcalcic hydrate, and for every two hundred and thirty-four parts byweight of monocalcic phosphate one hundred and fortyeight parts byweight of calcic hydrate are required. In place of using lime as achemical agent to combinewith the salt of phosphoric acid. to form aninsoluble precipitate, I may use any other chemical-such, for instance,as salts of barium, aluminium, or iron.

Calcic hydrate is, however, preferable for use in many cases eventuallycompletely stops filwith sugar solution. The other chemicals mentionedmay be used for the filtration of other solutions where it is desired toform an i insoluble precipitate.

During the process of adding the diatomaceous earth, the phosphoricsalt, and any of the other chemicals mentioned, the solution is keptpreferably in motion-in other words, agitated-by stirring or otherwise.

Instead of using the diatomaceous earth, phosphoric salt, and any of theother chemiin consequence the filtrate runs more or less whereconsiderable q uantities of the reagents are used the precipitate ofwhich the impurities iorm apart readily clogs the interspaces in thefilter bags or cloths and thus retards and tration.

It may be stated as the great and important mission of the diatomaceousearth in the cals in the order stated, I may reverse their i order orintroduce them in any order without materially aifecting the results.Preferably it is best to proceed as first stated.

The action of the chemical reagents em ployed is as follows: The calcichydrate or other alkaline earth, or any of the other chemi Calspreviously mentioned, combine chemically with the soluble salts ofphosphoric acid to form an insoluble compound, which in the case wherecalcic hydrate is employed consists principally of tri-calcic phosphate.This compound as it forms envelops and imprisons themechanically-suspended impurities existing in the solution, and in thecase where the chemical substances are introduced subsequently to theintroduction of the diatomaceous earth also takes up portions of thedi-' atomaceous earth and together form the precipitate which later isdeposited upon the filter-cloths or filter-bags.

After completing the operations indicated the solution is transmittedthrough the usual filter bags, presses, or similar devices, for thepurpose of removing all mechanically-suspended particles. This completesthe process.

Instead of using diatomaceo us earth alone,I may, prior to itsintroduction into the solution to be treated, combine it with a salt ofphosphoric acid of the characterindicated, and in such a manner as toproduce a dry preparation which may be conveniently packed or shippedand subsequently used in the process. It will be understood that whenthis dry preparation is employed the step hereinbcfore set forth oftreating the solution with an uncoinbined salt of phosphoric acid shouldbe omitted, the salt of phosphoric acid in the dry 1 preparation takingits place.

Filtration may be accomplished by the employment oi diatomaceous earthalone or by specified. In the latter case, however, un-

process described, to overcome these two difficulties. By virtue of itscharacteristic and peculiar porous structure, the diatomaccous earthpicks up and holds all mechanicallysuspended impurities, even the mostminute, and, furthermore, when forming a part of the precipitateproduced by the chemicals specified, it gives to this precipitate aporous structu re which permits the treated solution to flow absolutelyclear and more rapidly and for a longer time from the filter-bags, thuseffecting great saving and increased working capacity.

I wish it understood that I do not limit my improved process to thetreatment of sugarliquors, as it may be used for the filtration ofwater, oils, spirituous and other solutions containingmechanically-suspended impurities.

I claim as my invention- 1. The herein-described process of defecatingand purifying sugar and other solutions, which consists in subjectingsaid solutions to the action of a filtering agent having the generalrharacteristics of diatomaceous earth,

then to the action of a salt of which PO, is

the acid radical and which is soluble inwater, and a chemical of thecharacter indicated which will combine with said salt to form aninsoluble precipitate, and finally rcmoving the mechanical]y-suspendcdparticles from said solution.

2. The herein-described process of detecat ing and purifying sugar andother solutions, which consists in subjecting said solutions to theaction of a filtering agent having the general characteristics ofdiatomaceous earth, a salt of which PO, is the acid radical soluble inwater and an alkaline earth, such as calcic hydrate.

33. A step in the process of treating sugar and other solutions, whichconsists in introducing into said solutions a dry preparation composedof diatomaceous earth, and a salt of which PO, is the acid radical andwhich is soluble in water.

in testimony whereof I affix my signature in the presence of twowitnesses. the employment of the chemical reagents j FERDINAND GERIIARD\YlEtlLllANN.

Witn esses:

PAUL N. TURNER, lino. ii. BENJAMIN.

